Renner–Teller induced photodissociation of HCO in the first absorption band: Determination of linewidths for the Ã 2A″ K=0,1 states by filter-diagonalization

Abstract

Renner-Teller induced predissociation of HNO (Ã 1 A ″ ): Rotational-state dependent linewidths of quasibound statesAb initio study of the photodissociation of HCO in the first absorption band: Three-dimensional wave packet calculations including the X2A′−Ã2A ″ Renner-Teller couplingWe present new calculations on the Renner-Teller induced decay of the vibrational states of HCO(Ã 2 AЉ) using accurate ab initio potential energy surfaces. The dynamics calculations are performed by employing filter diagonalization and an absorbing optical potential in the exit channel. The objective of this investigation is twofold: the completion of earlier time-dependent wave packet calculations by determining resonance widths for all vibrational states for projection quantum number Kϭ1-up to 2.75 eV above the HϩCO(r e ) dissociation threshold-and the determination of the widths for the long-lived Kϭ0 states. In the latter case, a clear-cut J 2 (Jϩ1) 2 dependence, where J is the total angular momentum, is observed indicating that the rate determining step is K-resonance interaction between Kϭ0 and 2 states. The experimentally observed J-independent contribution ͑0.22-0.5 cm Ϫ1 ͒, which dominates the linewidth for small values of J, is not accounted for by our calculations. Arguments are put forward, that it is caused by spin-orbit interaction, which is not included in our treatment.

The unimolecular dissociation of HCO. V. Mixings between resonance states

“…4 for different values of J and K. They are in essence similar to the calculations described by Weiss et al 6,12 for the Renner-Teller induced dissociations of HCO and HNO, re-spectively, with the exception that only one electronic state, that is the ground state, is included. In short, we use the filter diagonalization ͑FD͒ method [13][14][15] and an imaginary potential in the exit channel in order to absorb the wave function at the edge of the grid.…”

Renner–Teller induced predissociation of HNO(Ã 1A″): Rotational-state dependent linewidths of quasibound states

“…In our previous work on RT coupling in HCO, [22][23][24] we closely followed the approaches of Petrongolo 25 and Goldfield et al 26 The key is a transformation from adiabatic electronic wave functions to diabatic ones, which-at linear geometries-are eigenfunctions of L z , the projection of the electronic angular momentum on the body-fixed z-axis ͑the C-O bond in HCO or the NO bond in HNO͒. 16 -21 for general discussions and reviews͒.…”

Quantum Mechanical Studies of Photodissociation Dynamics Using Accurate Global Potential Energy Surfaces

“…In the time-independent approach, the resonance widths are directly calculated by introduction of an absorbing complex potential in the H+CO exit channel. 116 The corresponding Hamilton matrix is complex symmetric with complex eigenvalues E 0 − iΓ/2.…”

“…In all cases J = K = 1. The error bars indicate the experimental results of Loison et al117 Reprinted, with permission of the American Institute of Physics, from Ref 116…”